Growth abnormalities, delayed onset of puberty and hypogonadism associated with homozygous sickle cell disease are presently unexplained. We intend to study cohorts of various aged male and female children with homozygous sickle cell disease by measurement of their height, weight, triceps and subscapular skinfold, sexual development and bone age. These findings will be correlated with changes in their circulating levels of human growth hormone, follicle stimulating hormone, lutenizing hormone, testosterone, androstenedione, dehydroepiandrosterone, estradiol, progesterone and somatomedin. In patients showing abnormalities hypertransfusion will be performed to determine what effect this will have on physical growth, sexual development or hormonal levels. The knowledge derived from this study could help in providing an understanding of the cause(s) for the growth abnormalities and delayed sexual development which occurs in sickle cell anemia and could provide a basis for amelioration of these untoward changes.